And a contingent that includes United Farm Workers co-founder Dolores Huerta, and singer Linda Ronstadt — a Californian who grew up in a Mexican American family in Tucson, Ariz. — will travel to Phoenix on Thursday for an event denouncing the legislation.

"I call this populist pandering. This law invites racial profiling; it requires racial profiling," said Thomas Saenz, president of the Los Angeles-based Mexican American Legal Defense and Educational Fund, who will join Huerta and Ronstadt at the event.

Saenz is preparing a lawsuit he said will be one among many challenging the law's constitutionality.

The law, which requires all Arizona police officers to demand proof of legal status if they have a reasonable suspicion that a person is an illegal immigrant is slated to take effect 90 days after Arizona's current legislative session.